Sofa bed



y 1966 L. B. EMMONS ETAL 3,258,737

SOFA BED Filed Dec. 11. 1964 6 Sheets-Sheet 1 1N VENTORS aye; 5-51/7063 GERTR U b HOLT 7UMLINSON y 1966 L. B. EMMONS ETAL 3,253,787

SOFA BED 6 Sheets-Sheet 5 Filed Dec. 11, 196-1 INVENTORS u s/vce 5. 671M 6 e /Q nfie HOLT TOML) sow y 1966 a. EMMONS ETAL ,787

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SOFA BED Filed Dec. 11, 1964 5 s t s 6 1 INVENTORS GERTRUDE HOLT TOMLINSON United States Patent 3,258,787 SOFA BED Laurence B. Emmons, Hotel Lancaster, 22 E. 38th St.,

New York, N.Y., and Gertrude Holt Tomlinson,

Seattle, Wash; said Tomlinson assignor to said Emrnons Filed Dec. 11, 1964, Ser. No. 417,539 15 Claims. (Cl. 5-43) This invention relates in general to sofa beds and more particularly to a sofa bed design which when used as a sofa will have a back that stands no more than thirty-two inches off the floor and when used as a bed will provide a mattress width thirty-eight inches. The sofa bed design of this invention also has the advantage of a stable construction and is such that the sleeping and sitting surfaces are completely separate.

There are a vast number of sofa bed designs, many of which seek various compromises between the optimum dimensions of a sofa and the optimum dimensions of a bed.

In designing the standard sofa, it is desirable to have a back which stands a total of no more than thirty-two inches off the floor, to have a seat which is approximately seventeen and one-half inches from the floor and which has a depth twenty-one inches. The sofa bed normally has a sitting surface, between arms, that is six feet, four inches wide. It is also preferable that the back slope 16 backward from a vertical plane. The seat dimensions and back slope are dictated by considerations of what is comfortable to the average person. The back height maximum dimension is in large part dictated by aesthetic considerations. A back any taller than thirty-two inches is generally not desired by the end user because of its bulky appearance. A sofa six feet, four inches between arms and over thirty-two inches high has an overpowering bulky impact. This maximum height dimension has become even more important in recent years where the eight to eight and a half foot ceiling has become increasingly standard. A sofa back which stands more than thirtytwo inches off the floor becomes aesthetically very objectionable, particularly in rooms having an eight foot ceiling.

It has long been standard for twin beds to have a thirtyeight inch wide sleeping surface. Although beds have been manufactured narrower than thirty-eight inches, such beds lack comfort. When asleep, the average person needs at least thirty-eight inches in order to achieve support for his arms and legs as he changes position. Obviously, a thirty-two inch maximum height sofa back is not adequate for a thirty-eight inch wide bed. That is a major problem to which this invention is addressed.

Accordingly, it is a major purpose of this invention to provide a sofa bed design which will permit achieving optimum dimensions as a sofa while providing the desired minimum width as a bed.

It is a more specific related purpose of this invention to provide a means whereby a thirty-two inch tall sofa back can be converted to be a thirty-eight inch wide horizontal sleeping surface.

It is a further purpose of this invention to achieve the above purposes without sacrificing optimum sofa seat dimensions.

It is another major purpose of this invention to provide a sofa bed design in which the base frame and back frame maintain their rigidity and dimensional alignment while being converted from one form to the other so as to increase the ease of handling during conversion from one form to the other.

For reasons of both convenience and hygiene it is highly desirable that a sofa bed isolate the sleeping surface from the surfaces employed when used as a sofa.

3,258,787 Patented July 5, 1966 If the sleeping surface is both isolated and kept from view when the sofa bed is used as a sofa, then the sleeping surface can be made up as a bed with sheets and blankets ready for immediate use on conversion into the bed form. This permits the making up of the sofa bed at the beginning of the day and puts it in condition for immediate use at any time during the day or whenever the person who is to use the bed wishes to retire. In old peoples homes, it has the additional advantage that the sofa bed can be used as a bed for resting purposes at various intervals during the day. Furthermore, by having entirely separate sleeping and sitting surfaces, it becomes possible to readily convert a bed into a sofa form without requiring that the bed be stripped down. This has considerable convenience in hotels and in other applications where the user may wish to rapidly and readily prepare his room for the reception of guests.

The hygienic reasons for keeping the sleeping surface isolated from the sitting surfaces arise out of the basic fact that upholstery does get permeated with dirt and as a practical matter it is rarely kept as clean as is a bed. By having the sleeping and sitting surfaces isolated from one another, the resident of the room has a private sleeping surface which he alone uses and yet has a separate sitting surface for guests.

Accordingly, it is a further major purpose of this invention to provide a sofa bed design which isolates the sleeping surfaces from the sitting surfaces.

The most practical way in which to keep the sitting surfaces and sleeping surface separated is to use the back side of the sofa back as the sleeping surface. This requires that the sofa back he pivoted about the base frame so that it can be pulled forward into the bed position. There are known sofa bed designs where the back is constructed in such a fashion as to permit it to be flopped forward in order to convert the sofa bed into a bed. However, such designs all involve the use of guide rails or raceways to guide the back as it is flopped forward and thus results in an item which does not have at all the aspect of a piece of furniture. The sofa bed neither looks like a sofa nor like a bed.

Thus, it is a purpose of this invention to provide a design which will permit the flopping forward of the sofa back into the bed position in a fashion that is consonant with the design of a piece of furniture which will look like a sofa when in that position and will look and'feel like a bed when in that position.

One of the major reasons why the prior art designs require the use of guide rails or other similar equipment is that the back frame has to be held in fairly strict alignment as it is flopped forward. If the back frame racks or gets out of alignment, then not only is wear very much fostered but the sofa bed soon becomes so misaligned that it does not open to a fully correct position nor will it close to the desired position. For example, the backbed portion may be intercepted by the sofa arm as it is pulled forward thereby causing considerable wear to the upholstery at the arms or, possibly, making it impossible to place the back into the bed position.

Accordingly, it is a further purpose of this invention to provide a sofa bed design in which the main frame and back frame are held in alignment with one another during all positions of conversion from sofa to bed and back again.

Further objects and purposes of this invention will become apparent from a consideration of the following detailed description and drawings, in which:

FIG. 1 is a side elevation view of a sofa illustrating the optimum dimensional relationships in sofa design;

FIG. 2 is an elevation view of the foot of a sofa bed, when converted to a bed, having optimum dimensions as shown.

FIG. 3 is an expanded perspective view of the basic framework of the sofa bed of this invention;

FIG. 4 is a perspective view of the mechanism employed around and about the point where the back frame pivots on the base frame;

FIG. 5 is a side view in partial cross-section of the sofa bed of this invention when used as a sofa;

FIG. 6 is an end view in partial cross-section of the FIG. 5 sofa bed when used as a bed (the FIG. 6 end view of the bed being in the same plane as the FIG. 5 side view of the sofa);

FIG. 7 is a view along the section 77 of FIG. 5 showing only one of the two front legs;

FIG. 8 is a view along the section 8-8 in FIG. 5 showing only one of the two back legs;

FIG. 9 is a view along the section 9-9 in FIG. 6 showing only one of the back legs;

FIG. 10 is a plan view of the back frame when converted into a bed; and

- FIG. 11 is a plan view of the base frame with the back frame removed.

With reference to the drawings, FIGS. 1 and 2 are included solely in order to illustrate the fundamental dimensional factors involved in the optimum design of sofas and beds. One of the major, if not the single major, problems in the design of a sofa bed is to achieve an appropriate compromise between the optimum dimensional design of a sofa and the optimum dimensional design of a bed. By means of this invention, no such compromise is required because optimum dimensional goals are achieved in both the sofa position and the bed position.

It will aid in the understanding of the detailed description of the rest of the drawings to keep in mind the dimensional relationship shown in FIGS. 1 and 2 since many of the specific details of the mechanics and linkages and cam design of the sofa bed of this invention arise out of a need to achieve the dimensions shown in FIGS. 1 and 2. The reasons why such matters as the seat dimensions are critical in the design to be described is that the twenty-one inch seat depth limits the position along the base frame at' which the back frame can be made to pivot. The seventeen and one-half inch distance from the floor to the upholstery of the seat imposes a limitation on the height of the base frame and thus means that the pivot point between he back frame and the base frame has to be less than that distance above the floor. Furthermore, the 16 backward slope which is desirable for the back frame means that when the back frame is pivoted counterclockwise (as seen from the side shown in FIG. 1) there must be room between the lower end of the back frame and the floor so that the lower end of the back frame can swing around without being stopped by the floor. These and other dimensional considerations will be discussed in connection with the particular design described in detail herein.

This invention is described in connection with an institutional sofa bed because it has particular usefulness and applicability in places such as hotels and old peoples homes where the same piece of furniture must be used as a sofa during the day and a bed at night and must be ready for immediate use. However, the basic features of the bed would be the same even if a somewhat different environmental use, such as home use, were intended.

FIG. 3 is an exploded perspective View of the sofa bed of this invention showing only the main framework. FIG. 4 is a perspective view showing the main linkages and pivoting techniques employed. FIG. 3 shows the base frame 10 (which includes the legs 12) and the back frame 14, shown spaced from the base frame for ease of visualization. A cradle 16 rigidly attached to each end of the base frame 10 is adapted to receive and pivotally hold trunnions 18 which are rigidly connected to either end of the back frame 14. The back frame 14 pivots in the cradle 16 on the trunnions 18 when the sofa bed is being converted from one form to the other. As Will be explained in connection with the other figures, and particularly in connection with FIG. 10, the back frame 14 is meshed with an extension frame 26. The extension frame 26 is free to move relative to the back frame 14 laterally within the major plane of the back frame 14. The extension frame 26 extends when this sofa bed is converted into a bed, so that the desired full thirty-eight inches of mattress Width is available. The extension frame 26 retracts into the back frame 14 when converted into a sofa so that the back can be limited to thirty-two inches from the floor and so that the back frame 14 will clear the wall and the floor when being swung from sofa to bed and back again. FIG. 3 illustrates the back frame 14 alone because it is only the back frame 14 which is supported on the base frame 10 by the trunnions 18. The extension frame 26 is supported at a different longitudinal position on the base frame 10 so that when the back frame 14 pivots, the extension frame 26 describes a different arc than does the back frame 14 and in this fashion the extension frame 26 is caused to move laterally relative to the back frame 14 at the same time that both the back frame 14 and extension frame 26 are pivoting.

Each trunnion 18 is mounted in a cammed stabilizing fin 20 which fin 20 in turn is rigidly connected to an end of the back frame 14. When the back frame 14 rotates forward relative to the base frame 10, the edge of each back fin 20 rides against the edge of one of two anchored fins 22. The anchored fins 22 are removably anchored, through anchor 24, to the floor. When the sofa bed is being converted to a bed, the cammed fin 20 rides against a forwardly facing edge of the anchored fin 22 in such a fashion as to push the entire sofa bed forward, away from the wall.

Each anchored fin 22 rides in a channel formed by spaced apart legs of the two horizontal angles 56 at each side of the base frame 10. The bottom edge of the anchored fin 22 is also held within a vertical slot cut into the vertical leg of the horizontal back bracing angle 25. The fin 22 is shaped so that it remains captive not only in the channel between the angles 56 but also in the slot in the angle 25 when the base frame 10 is pushed forward to the bed position. In this fashion a great deal of rigidity and alignment is maintained for the base frame 10 as it moves toward and away from the wall. The fins 22 by holding the base frame 10 at each end make sure that the frame 10 does not twist or turn or rack as the frame 10 moves forward and back.

It is because this fin 22 is anchored that it becomes possible to align and stabilize the whole sofa bed. The anchor 24 and pin 38 (see FIGS. 5 and 6) which hold the fin 22 also hold the entire sofa bed against the wall. But for the anchor 24, there would be no fixed point to force the main frame 10 forward and pull the main frame 10 back during conversion from one form to the other.

The cammed stabilizing fin also rides within the channel between the two end angles 56 (see FIG. 5) thereby keeping the back frame '14 aligned with the base frame 10 as the back frame 14 rotates on the trunnions 18. The cammed fin 20* has a large surface area so that it maintains wide area contact with the cross bar angles 56 and thus acts as an effective aligning and stabilizing mechanrsm.

With the above general arrangement in mind, FIGS. 5 and 6 can be more readily comprehended. FIGS. 5 and 6 show most of the essential features of this invention. The cammed stabilizing fin 20 which is mounted on the back 14 pivotally supports the back 14 on the base 10 by means of the trunnion 18 in the cradle 16. It should be recognized that FIGS. 5 and 6- illustrate linkages and supports between the back 14 and base 10 on one end of the sofa bed. All of these features are duplicated on the other end. The extension frame 26 is not supported by the trunnion 18 but rather is supported by means of a hinge 28. The two-piece hinge 28 pivots at point 30 with one leg attached to the extension frame 26 and the other leg attached to a bracket 32 on the base frame 18. The extension frame 26 (as will be shown more clearly in FIG. is trapped within the back frame 14 with only a single degree of freedom of motion relative to the back frame 14; specifically, the extension frame 26 is free to translate laterally to the back frame 14 so that the back expands when in the bed form to provide a wider sleeping surface and contracts when in the sofa form to provide a lower back height. The freedom of motion of the extension frame 26 relative to the back frame 14 is readily achieved by having the lateral struts 27 of the extension frame feed through openings in the longitudinal support bars 29 of the back frame 14.

The back frame 14 is supported at pivot point 18 and the extension frame 26 is supported at pivot point 30. Accordingly, the axis about which the back frame 14 rotates is displaced from the axis about which the extension frame rotates. The two frames will describe different arcs when rotated. The different arcs can be accommodated only by providing freedom for the extension frame 26 to move in a lateral direction relative to the back frame 14. In this fashion the extension frame 26 is forced to its extended position when the back frame 14 is rotated counter-clockwise to the bed position.

The mattress 34 is made of a compresssible material such as foam rubber so that a segment of the mattress 34A can be caused to expand and contract with the extension and retraction of the extension frame 26. The mattress segment 34A need not even be the same material as is the mattress 34. Even if the mattress segment 34A does not provide the same full support as does the rest of the mattress 34, that will cause no material diminution of the benefit of obtaining a full thirty-eight inch width mattress since the six inches at the edge of the mattress does not have to carry the main body weight. As long as the segment 34A provides adequate support for the hand, foot or limb that may be resting threeon, it performs satisfactorily.

The base frame 10 has front legs 12F and back legs 12B on casters 36 so that the sofa bed is free to move. This movement is necessary because the sofa bed in both forms (that is when as a sofa and when as a bed) is desired to be against a wall. This means that when converted from a sofa into a bed, the base frame 10 must move away from the wall so that there will be room for the extension frame 26 and mattress portion 34A to expand. In order to reduce carpet wear it is desirable that the casters 36 be as large and wide as possible, thereby providing a large bearing surface. The caster size on the front legs 12F is limited by aesthetic considerations. Thus it is preferable to provide an intermediate set of legs 12M (see FIGS. 3 and 6) which bear the forward load and to which casters 36 of any desired size may be attached. The length of the front leg 1121 is such that the caster 36 under it will not normally touch ground when no one is sitting or lying on the sofa bed.

An anchor 24 with an anchor pin 38 is fastened to the floor at the baseboard of a wall. As may be seen in FIG. 9, the anchored fin :22 has a rear portion which is bent at 90 to stiffen the fin 22. In this rear portion there is an opening 48 which fits over the anchor pin 38. Thus the anchored fin 22 is prevented from moving away from the wall when the base frame 10 is pulled away from the wall. There are two anchored fins 22, one at each side of the sofa (end of the bed). Each anchored fin 22 fits within a channel in the cross bars '56 of the base frame 10. Since there is one fin 22 at each end of the base frame 10, these fins 22 keep the base frame 10 from racking as it is pulled away from the wall when converted into a bed. The forwardly facing edge 42 of the anchored fin 22 contacts an edge of the cammed stabilizing fin and serves as the surface against which the cammed fin 20 pushes when the sofa bed is converted into the bed form.

The trunnions 18 are rotatably held in the cradle '16 to hold the back frame 14in position where it can be pivoted relative to the base frame 10, the pivot point being the axis of the trunnion-s 18. The extension frame 26 is not connected to the cammed fin 20 and thus is not supported by the trunnions 18. When the back frame 14 rotates, it drags the extension frame 26 along. But the extension frame 26 is supported by the hinge 28 so that the extension frame 26 rotates about the pivot point 30. Thus the extension frame 26 describes an entirely different are than does the back frame 14. In this fashion, the extension frame 26 is forced to its extended position when the back frame 14 is rotated into the bed position and is pulled back into its retracted position when the back frame 14 is rotated into the sofa position.

It may be noticed that the trunnion 18 and cammed fin 20 arrangement permits rotation of the back frame 14 about the base frame 10 Without requiring the use of hinges. This feature minimizes maintenance problems because there is no hinge pin which does any substantial amount of work and that may as -a consequence become worn out. In general, the surfaces where work is done are spread out over a sufficiently wide area so that wear is kept to a minimum and, as a consequence, maintenance is minimized.

For schematic purposes, FIG. 3 illustrates the cammed fin 20 as directly hun-g onto the side bar of the back frame 14 through the trunnion 18 and a straight bracket. A workable arrangement is best seen in FIG. 4, where an L-shaped bracket 43 is used to rigidly connect the fin 20, through the trunnion .18, to the back frame 14-.

As may be seen from FIGS. 5, 6 and 7, the other important operative elements which make possible the conversion of this sofa bed from one form to the other, include:

(a) A helical spring 44 which is connected at its back end to a back leg 12B of the base frame 10 and is connected at its front end to a link 45, which link 45 in turn is pivotally connected at point 46 to the cammed stabilizing fin 20. When in the sofa position, the helical spring 44 tends to hold the cammed fin 20 against counterclockwise motion and thus tends to hold the back .14 in position. As may be seen from FIG. 6, the point 46 on the link 45 has been rotated to a position below the trunnion 18, when the sofa bed is in the bed position. Accordingly, the spring 44 tends to prevent the cammed fin 20 from rotating in a clockwise position and thus tends to hold the back frame 14 in the bed position once that position has been attained. However, a relatively small clockwise rotation of the back frame 14 will bring the point 46 to a position above the trunnion 18 so that the spring 44 will serve to assist the rotation of the back frame 14 into the sofa position during most of the are that must be traversed in conversion to the sofa position. By this design, gravity and the spring 44 assist one another to hold the back in either end position (as a bed or as a sofa) but oppose one another during most of the arc of travel from one end position to the other.

(b) A leaf spring 48 is placed directly under the cammed fin 20 so that the leaf spring 48 is bowed when the sofa bed is in the bed position. The leaf spring thus pushes up on the cammed fin 20 to assist in converting from a bed condition to a sofa condition. The leaf spring 48 is slotted in part to accommodate the anchored fin 22.

(c) A slotted link 50 is pivotally connected at point 51 to cammed fin 20. The slot 52 rides on -a pin 54, which pin 54 is attached to the back fin 22. The major purpose of this slotted link 50 is to pull the back frame 14 and base frame 10 back toward the wall when converting the bed into a sofa. Since it is important that the frames 10 and 14 not move back toward the wall until the back frame 14 has rotated sufficiently to clear the wall, it is important that the link 50 not become effective until a pre-determined rotation of the back frame 14 has been completed.

The slot 52 in the link 50 achieves this delay function. As may best be seen by looking at FIG. 6, as the back ,14- is rotated in a clockwise direction, the link 50 will be pulled by the cammed fin 20 to the left. The pin 54 will ride in the slot 52 until the pin 54 hits against the right hand edge of the slot 52. At that point, and not until that point, the link 50 will begin to pull the frame 10, 14 and the triangular fin 22 together. Since the back fin 22 is anchored, this means that the frame 10, 14 will travel back toward the wall. Because of the delay action due to the slot 52, the back frame .14 and mattress 34 will have rotated to a position Where the wall will not interfere with further rotation after the backward movement of the frame 10, 14 is started.

(d) A pin 55 is rotatably mounted to the back fin 22 at a position just under the horizontal leg of the cross bar angle 56. This pin 55 keeps the back fin 22 from being lifted d the base frame and in particular keeps the fin 22 down in contact with the vertical leg of the cross bar angle 56. This is important when the fin 22 is tilted to permit removing the sofa bed a distance from the wall. It is also important in case there is any tendency for the cammed edge of the cammed fin to bind against the forwardly facing edge 42 of the back fin 22 or to get under the back fin 22 and thereby cause the fin 22 to lift upward. Thus, at the same time that the pin prevents the back fin 22 from being lifted off the horizontal cross bar 56 (when the fin 22 is tilted) the pin 55 also serves as 'a pivot point about which the fin 22 rotates when it is lifted off the anchor pin 38.

(e) A curved slot 53 in the cammed fin 22 is included in order to permit the incorporation of a friction brake which, together with the springs 44 and 48, oppose gravity and assist in preventing the back 14 and mattress 34 combination from falling over clockwise too precipitously when converting from a sofa to a bed. The cammed fin 20 fits within the channel between the two spaced apart metal angles 56 which form the end member of the base frame 10. A bolt 60 joins these two spaced apart angles 56 and can be tightened or loosened so as to increase the friction between the surface of the cammed fin 20 and the surfaces of the vertical legs of the two angles 56. The curved slot 53 is included to permit the bolt 60 to pass through the cammed fin 20 and yet all-ow the fin 20 to rotate. A second bolt is employed to hold the two cradles 16 on each end of the base frame 10 to the horizontal cross bar angles 56. The slot 53, as shown, is made large enough so as to accommodate the bolt head of the second bolt as well, thereby making it unnecessary to countersink for an appropriate screw.

Cleaning and maintenance personnel will find it necessary to move the sofa bed of this invention entirely away from the wall for any one of a number of purposes. To facilitate such removal, the anchored back fin 22 is removably anchored, as has been described, to the anchor pin 38. It is simply necessary to tilt the back fin 22 up about a pivot point established by the pin 55 to clear the anchor pin 38 and permit moving the bed entirely away from the wall. In order for the fin 22 to be free to so tilt, the forwardly facing edge 42 of the fin 22 must be cut so as to leave a gap between the upper portion of that edge 42 and the cammed edge of the cammed fin 20, which design may readily be seen in FIG. 6.

One advantage of the design of this invention is that the same spring web is used to support the mattress when in the bed position and to support the back cushions when in the sofa position. FIGS. 3 and 10 show a portion of the spring web. The spring web is composed of a plurality of small helical springs 63 which hold steel straps 64 to the perimeter members of the back frame 14. As is best seen in FIG. 6, the small helical springs 63 are hooked at one end to an anchor angle 65, which in turn is aflixed to the perimeter members of the back frame 14.

One of the major reasons for employing the design which permits the back frame 14 to rotate about a longitudinal axis is that such a design isolates the sleeping surface from the sitting surface. The sanitary conditions for such a design have been discussed. In addition, this design permits making up of the mattress 34 so that it is available for immediate use. The sheets and blankets can all be made up and tucked in because the mattress 34 is entirely out of sight when in the sofa position.

When this sofa bed is in the sofa position, the mattress 34 must be held onto the back frame 14. As is obvious from a consideration of FIG. 5, the mattress 34 would simply fall off the frame 14 if not positively held thereon. Indeed, the mattress 34 requires wide area anchoring if it is not to sag within the sofa position. In addition, wide area anchoring will avoid points of great stress that might result in ripping the ticking, This is achieved by the use of a metal anchor frame 66 which is attached to the anchor angle 65.

The anchor angle 65 thus also serves the important purpose as an anchor for the anchor frame 66 to which the mattress 34 ticking is attached. In the design of the sofa bed it is preferred to use a mattress which has attached to it a pleat 67 (see FIG. 5) that runs around the perimeter of the mattress 34 along the under side of the mattress. This pleat 67 is in cross section in the form of a loop that is joined to the rest of the ticking at a point at least two inches in from the edge of the mattress 34. This two inch distance is to permit adequate room for tucking sheets and blankets under the mattress. The pleat 6'7 loop is wide enough so that it runs from the point of attachment to the mattress out to the edge of the mattress. Within the loop formed by the pleat there is deployed a metal anchor frame 66 that runs the entire perimeter of the mattress 34. This anchor frame 66 is bolted to the anchor angle 65 at a large number of positions. The mattress is, by this means, held along the nearly two inch wide surface of the anchor frame 66, which anchor frame 66 is as long as the perimeter of the mattress 34. Thus localized points of high stress on the ticking or fabric of the mattress are avoided so that wear and maintenance are minimized.

The design of this sofa bed has been purposely geared to the requirements and needs of the elderly. The sofa bed has been designed with various springs and counterbalance features that have sufiiciently different operating characteristics so that the back-mattress portion can be moved from one position to another with relative ease at all points along the arc of rotation between positions. The sofa bed has also been designed in such a fashion that it can be readily and quickly converted from bed to sofa and back again so that it can be used for frequent naps during the day. Also, as has been pointed out above, the basic structural design permits a final furniture design that affords an aesthetically pleasing sofa and a comfortable bed that can be readily incorporated into the many new facilities which are being built for elderly people.

The many features which make the sofa bed of this design especially useful and adaptable to the uses of elderly people are also of much broader application. The low maintenance cost features, the ease of handling, the ready convertibility from sofa to bed and back again, are all features that commend the design of this sofa bed to all institutional uses, including general hotel applications.

It should also be noted that the elements of the sofa bed framework are such that the entire sofa bed can be very readily knocked-down and very readily assembled. In addition, when knocked-down, the various components can be readily packaged and shipped. The ease of shipping the separate components coupled with the relative ease of assembling has the considerable commercial advantage of saving on freight and storage costs.

The technique of adjusting the position of the frame by having the cammed fin 2% rotate to exert a force against the stabilizing fin 22 is a fundamental approach which has application to a much broader range of furniture design than that of a sofa bed. Wherever it is desired to adjust the position of all or a major part of a piece of furniture (such as a seat in a bus or train) this basic approach has certain distinct advantages. The use of a cammed fin to exert pressure against the stabilizing fin 22 and thereby adjust the frame to which the cammed fin 20 is attached has the broad advantages of: (1) greatly reducing maintenance problems by removing elements such as gears and hinges that are likely to require replacement because of wear or breaking; (2) making it possible to achieve adjustment over an entire range of positions and not just a limited few which are determined by notch locations; and (3) performing two functions with the stabilizing fin 22, an adjustment function and a stabilizing function, thereby providing an exceptionally efficient use of elements.

In this and other fashions it should be clear that the true scope of this invention is not limited to the embodiment disclosed. Accordingly, it shall be understood that the following claims are to be interpreted to cover the full scope of this invention.

What is claimed is:

1. A sofa bed frame comprising:

a base frame,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame.

2. A sofa bed frame comprising:

a base frame having a forwardly projecting channel therein,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame, and

a back fin projecting within said channel, said back fin being adapted to beanchored to ground, whereby said fin when so anchored prevents transverse movement of said base frame while permitting back and forth movement of said base frame, and

means to exert a force between said back fin and said base frame when said back frame is rotated from the sofa position to the bed position, thereby causing said base frame to move forward and create room for the extension of said extension frame.

3. A sofa bed frame comprising:

a base frame having a forwardly projecting channel therein,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame,

a back fin projecting within said channel, said back fin being adapted to be anchored to ground, whereby said fin when so anchored prevents transverse movement of said base frame while permitting back and forth movement of said base frame,

means to exert a force between said back fin and said base frame when said back frame is rotated from the sofa position to the bed position, thereby causing said base frame to move forward and create room for the extension of said extension frame, and

link means between said base frame and said back frame to exert a backward force on said base frame when said back frame is rotated from the bed position to the sofa position, said link means including a lag means to assure that the back frame will rotate a pre-determined number of degrees toward the sofa position before said link means is effective to pull back said base frame.

4. In a sofa bed design having a back frame pivotally mounted on a base frame wherein the upholstery on one surface of said back frame will be used in the sofa position and a mattress on the other surface of said back frame will be used in the bed position, the improvement to ease conversion from one position to the other comprising:

a helical spring between said back frame and said base frame, said helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

a downwardly projecting cammed surface attached to said back frame, said cammed surface being cammed to project further down when said back frame is rotated to said bed position than when said back frame is rotated to said sofa position,

a leaf spring attached to said base frame, said' leaf spring being deployed below said downwardly projecting cammed surface whereby said leaf spring will be distended by said cammed surface when said back frame is rotated into said bed position, and

adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

5. A sofa bed frame comprising:

a base frame,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame,

a helical spring between said back frame and said base frame, said helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

a downwardly projecting cammed surface attached to adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

In a sofa bed having a back frame pivotally mounted on a base frame, the stabilizing mechanism comprising:

pair of forwardly projecting back fins, one at each end of said base frame, said back fins having a forwardly facing edge, said back fins being adapted to be anchored to ground,

a pair of channels, one each being formed at each end of said base frame, each one of said back fins projecting within a separate one of said channels, whereby said base frame is free to move parallel to the plane of said back fins and is held against movement transverse to the plane of said back fins, and

pair of cammed fins rigidly mounted to said back frame, each one of said cammed fins having a cammed surface adapted to ride on one of said forwardly facing edges of said back fins, said cammed fins being cammed to push against said forwardly edges of said back fins when said back frame is rotated into the bed position,

whereby the rotation of said back frame from sofa position to bed position when said back fins are anchored will rotate said cammed fins to exert a force between said cammed fins and said back fins thereby transmitting a forward force through said back frame to said base frame and causing said base frame to move forward.

A sofa bed framework comprising:

a base frame movable in a forward and backward direction, said base frame including a channel at a first end,

a forwardly projecting anchored fin at said first end of said base frame, said fin being captive within said channel, there being wide surface contact between the walls of said channel and the surface of said fin, whereby said base frame is free to move in a direction parallel to the plane of said fin, said forwardly projecting fin having a forwardly facing edge,

means to removably anchor said forwardly projecting fin to the ground, back frame pivotally mounted on said base frame along a first axis,

an extension frame pivotally mounted to said base frame a cammed fin rigidly mounted to said back frame and having a cammed edge adapted to ride on said forwardly facing edge of said anchored fin, said cammed fin being cammed to push against said forwardly facing edge of said back fin when said back frame is rotated from a bed position to a sofa position.

A sofa bed frame comprising:

a base frame,

back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained :12 within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame,

a pair of forwardly projecting back fins, one at each end of said base frame, said back fins having a for wardly facing edge, said back fins being adapted to be anchored to ground,

a pair of channels, one each being formed at each end of said base frame, each one of said back fins projecting within a separate one of said channels, whereby said base frame is free to move parallel to the plane of said back fins and is held against movement transverse to the plane of said back fins, and

a pair of cammed fins rigidly mounted to said back frame, each one of said cammed fins having a cammed surface adapted to ride on one of said forwardly facing edges of said back fins, said cammed fins being cammed to push against said forwardly facing edges of said back fins when said back frame is rotated into the bed position,

whereby the rotation of said back frame from sofa position to bed position when said back fins are an chored will rotate said cammed fins to exert a force between said cammed fins and said back fins thereby transmitting a forward force through said back frame to said base frame and causing said base frame to move forward.

9. A sofa bed frame comprising:

a base frame,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel-to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame,

a pair of forwardly projecting back fins, one at each end of said base frame, said back fins having a forwardly facing edge, said back fins being adapted to be anchored to ground,

a pair of channels, one each being formed at each end of said base frame, each one of said back fins projecting within a separate one of said channels, whereby said base frame is free to move parallel to the plane of said back fins and is held against movement transverse to the plane of said back fins,

a pair of cammed fins rigidly mounted to said back frame, each one of said cammed fins having a cammed surface adapted to ride on one of said forwardly facing edges of said back fins, said cammed fins being cammed to push against said forwardly facing edges of said back fins when said back frame is rotated into the bed position,

whereby the rotation of said back frame from sofa position to bed position when said back fins are anchored will rotate said cammed fins to exert a force between said cammed fins and said back fins thereby transmitting a forward force through said back frame to said base frame and causing said base frame to move forward, and

link means between said base frame and said back frame to exert a backward force on said base frame when said back frame is rotated from the bed position to the sofa position, said link means including a lag means to assure that the back frame will rotate a pro-determined number of degrees toward the sofa position before said link means is effective to pull back said base frame.

10. A sofa bed framework comprising:

a base frame movable in a forward and backward direction, said base frame including a channel at a first end,

a forwardly projecting anchored fin at said first end of said base frame, said fin being captive within said channel, there being wide surface contact between the walls of said channel and the surface of said fin, whereby said base frame is free to move in a direc tion parallel to the planes of said fin, said forwardly projecting fin having a forwardly facing edge,

means to removably anchor said forwardly projecting fin to the ground,

a back frame pivotally mounted on said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in solely one direction along a plane substantially parallel to the main plane of said back frame,

a cammed fin rigidly mounted to said back frame and having a cammed edge adapted to ride on said forwardly facing edge of said anchored fin, said cammed fin being cammed to push against said forwardly facing edge of said back fin when said back frame is rotated from a sofa position to a bed position,

a slotted link pivotally mounted at one end to said cammed fin and having a lengthwise slot spaced from said pivoted end, and

pin means attached to said anchored fin and extending through said slot of said link, said pin means being adapted to ride within said slot, said pin means extending through the forward portion of said slot when said cammed fin is in the bed position, whereby rotation of said cammed fin from said bed position to said sofa position will cause said slot to ride over said pin until said pin contacts the back end of said slot at which point said pin will pull said base frame back toward the wall as said sofa position is attained.

11. In a sofa bed design having a back frame pivotally mounted on a base frame wherein the upholstery on one surface of said back frame will be used in the sofa position and a mattress on the other surface of said back frame will be used in the bed position, the improvement to ease conversion from one position to the other comprising:

mounting means to pivotally mount said back frame to said base frame along an axis intermediate between the forward and backward edges of said back frame, whereby said back frame will be partially counterbalanced during rotation about said axis,

a helical spring between said back frame and said base frame, said helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

a downwardly projecting cammed surface attached to said back frame, said cammed surface being cammed to project further down when said back frame is ro tated to said bed position than when said back frame is rotated to said sofa position,

a leaf spring attached to said base frame, said leaf spring being deployed below said downwardly projecting cammed surface whereby said leaf spring will be distended by said cammed surface when said back frame is rotated into said bed position, and

adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

12. A sofa bed frame comprising:

a base frame having a forwardly projecting channel therein,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame, and

a back fin projecting within said channel, said back fin being adapted to be anchored to ground, whereby said fin when so anchored prevents transverse movement of said base frame while permitting back and forth movement of said base frame,

means to exert a force between said back fin and said base frame when said back frame is rotated from the sofa position to the bed position, thereby causing said base frame to move forward and create room-for the extension of said extension frame,

a helical spring between said back frame and said base frame, said helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

said back frame including a member projecting outwardly from said first axis and positioned at an angle so as to project further down when said back frame is rotated to said bed position than when said back frame is rotated to said sofa position,

a leaf spring attached to said base frame, said leaf spring being deployed below said projecting member whereby said leaf spring will be distended by said member when said back frame is rotated into said bed position, and

adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

13. In a sofa bed having a back frame pivotally mounted on a base frame, the stabilizing mechanism comprisa pair of forwardly projecting back fins, one at each end of said base frame, said back fins having a forwardly facing edge, said back fins being adapted to be anchored to ground,

a pair of channels, one each being formed at each end of said base frame, each one of said back fins projecting within a separate one of said channels, whereby said base fra-rne is free to move parallel to the plane of said back fins and is held against movement transverse to the plane of said back fins,

a pair of cammed fins rigidly mounted to said back frame, each one of said cammed fins having a cammed edge adapted to ride on one of said forwardly facing edges of said back fins, said cammed fins being cammed to push against said forwardly facing edges of said back fins when said back frame is rotated into the bed position,

whereby the rotation of said back frame from sofa position to bed position when said back fins are anchored will rotate said cammed fins to exert a force between said cammed fins and said back fins thereby transmitting a forward force through'said back frame to said base frame and causing said base frame to move forward,

a helical spring between said back frame and said base frame, said'helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

said cammed edge of said cammed fin being cammed to project further down when said back frame is rotated to said bed position than when said back frame is rotated to said sofa position,

a leaf spring attached to said base frame, said leaf spring being deployed below said cammed fin Whereby said leaf spring will be distended by said ca'rnmed fin when said back frame is rotated into said bed position, and

adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

14. A sofa bed frame comprising:

a base frame,

a back frame pivotally mounted to said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in a direction substantially perpendicular to said second axis and along a plane substantially parallel to the main plane of said back frame,

whereby the rotation of said back frame relative to said base frame will cause said extension frame to rotate relative to said base frame about said second axis thereby forcing said extension frame to translate relative to said back frame,

a pair of forwardly projecting back fins, one at each end of said base frame, said back fins having a forwardly facing edge, said back fins being adapted to be anchored to ground,

a pair of channels, one each being formed at each end of said base frame, each one of said back fins projecting within a separate one of said channels, whereby said base frame is free to move parallel to the plane of said back fins and is held against movement transverse to the plane of said back fins,

a pair of cammed fins rigidly mounted to said back frame, each one of said cammed fins having a cammed surface adapted toride on one of said forwardly facing edges of said back fins, said cammed fins being cammed to push against said forwardly facing edges of said back fins when said back frame is rotated into the bed position,

whereby the rotation of said back frame from sofa position to bed position when said back fins are anchored will rotate said cammed fins to exert a force between said cammed fins and said back fins thereby transmitting a forward force through said back frame to said base frame and causing said base frame to move forward,

a helical spring between said back frame and said base frame, said helical spring being under minimum tension when said sofa bed is in the sofa position and under maximum tension when in the bed position,

said cammed edge of said cammed fin being cammed to project further down when said back frame is rotated to said bed position than when said back frame is rotated to said sofa .position,

a leaf spring attached to said base frame, said leaf spring being deployed below said cammed fin whereby said leaf spring will be distended by said cammed fin when said back frame is rotated into said bed position, and

adjustable friction means between said back frame and said base frame to permit selection of a desired degree of friction between said frames as said back frame is rotated.

15. A sofa bed framework comprising: a base frame movable in a forward and backward direction, said base frame including a channel at either end,

forwardly projecting anchored fins-at either end of means to removably anchor said forwardly projecting fin to the ground,

a back frame pivotally mounted on said base frame along a first axis,

an extension frame pivotally mounted to said base frame along a second axis parallel to and displaced from said first axis, said extension frame being constrained within said back frame to have freedom of movement relative to said back frame in solely one direction along a plane substantially parallel to the main plane of said back frame,

cammed fin at either end of and rigidly mounted to said back frame, each of said cammed fins having a cammed edge adapted to ride on a respective one of said forwardly facing edge, of said anchored fins, said cammed fins being cammed to push said forwardly facing edges of said back fins when said back frame is rotated from a sofa position to a bed position,

a pair of slotted links, one each pivotally mounted at a first end to a respective one of said cammed fins and having a lengthwise slot spaced from said first end,

pin means attached to each one of said anchored fins,

helical spring means between said back frame and said base frame to assist in lifting said back frame from a bed position to a sofa position,

leaf spring means under said cammed fin to assist in lifting said back frame from a bed position to a sofa position, and

adjustable friction means between said cammed fin and said base frame to permit selection of a resistive force to ease the descent of said back frame from a sofa position to a bed position.

References Cited by the Examiner UNITED STATES PATENTS FRANK B.

Harris et al 543 Reynolds et al 5--32 X Lorenz 5-43 Hopeman et al. 543 Warshaver 558 SHERRY, Primary Examiner.

ASM R A- NUNBERG, Assistant Examiner. 

1. A SOFA BED FRAME COMPRISING: A BASE FRAME, A BACK FRAME PIVOTALLY MOUNTED TO SAID BASE FRAME ALONG A FIRST AXIS, AN EXTENSION FRAME PIVOTALLY MOUNTED TO SAID BASE FRAME ALONG A SECOND AXIS PARALLEL TO AND DISPLACED FROM SAID FIRST AXIS, SAID EXTENSION FRAME BEING CONSTRAINED WITHIN SAID BACK FRAME TO HAVE FREEDOM OF MOVEMENT RELATIVE TO SAID BACK FRAME IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO SAID SECOND AXIS AND ALONG A PLANE SUBSTANTIALLY PARALLEL TO THE MAIN PLANE OF SAID BACK FRAME, WHEREBY THE ROTATION OF SAID BACK FRAME RELATIVE TO SAID BASE FRAME WILL CAUSE SAID EXTENSION FRAME TO ROTATE RELATIVE TO SAID BASE FRAME ABOUT SAID SECOND AXIS THEREBY FORCING SAID EXTENSION FRAME TO TRANSLATE RELATIVE TO SAID BACK FRAME. 